Monthly Archives: June 2014

Albert Einstein felt nature would not permit such things to exist, despite his theory of general relativity allowed such a possibility. It was unthinkable for him to have an enormous star; hundreds of times bigger than our sun could vanish from the universe. An American journalist first named black holes in 1968 reporting on an American scientific meeting. American physicist, John Wheeler was the first one to describe an area of space which was “empty” and which “swallowed everything” including light. Pierre-Simon Laplace and John Mitchell considered that such objects existed where the gravitational force was so great that light cannot escape in 18th Century, and were called “black stars” or “cold stars“. In ancient Indian scripture, Mandukya Upanishad, probably composed around the second millennium BCE, talks about Vishwaruchi, which absorbs everything in the universe – Black Hole. Black holes were considered as scientific curiosities in the first half of the twentieth century and belonged largely in science fiction. It is only in the last couple of decades that their existence accepted by the scientific community. It was popularised by movies such as Star Wars and TV programmes like Star Trek, Dr Who, Battle star Gallactica and Star gate. Authors such as Larry Niven and Frederick Pohl used them as their theme in their novels. We now know that gravity does affect the time. If you are climbing a skyscraper, wearing an ultra-sensitive clock you will notice that the clock moves slightly slower as you reach the top, albeit by a billionth of a second. The difference on a GPS satellite can be quite significant and hence the clocks on these satellites are constantly readjusted. A black hole has enormous gravitational pull, strong enough to even hold the light in it, and nothing can escape a black hole. Escape velocity from the weak earth’s gravity is about 7 miles per second. Light travels at about 186282 miles per second. Even this velocity is not enough to get light out of the gravitational pull of a black hole. The only thing we know that is capable of travelling faster than light, is a quantum particle called Tachyon. Even this has been described in the Mandukya Upanishad as Manojava. The characteristics of both objects and particles are uncannily similar. Varahamihira described what could only be a gravitational force when he said, that there must be a force that keeps object stuck on the surface of the earth. Later in the seventh century, Brahmagupta said the same thing about falling objects – “bodies fall towards the earth as it is in the nature of the earth to attract bodies.” Sayana, a fourteenth century mathematician and teacher in Vijayanagara court, commenting on Rigveda, Book one, hymn 50, has described what appears to be the speed of light. He quotes sunlight travelling 2202 yojanas in half a “nimisha.” Taking each Yojana to be about 9 miles long and a nimisha is about 16/75thof a second; it works out to around 185794 miles per second. That is a very close approximation of the speed of light. He was writing in the fourteenth century AD about a Vedic composition probably dating back to 3000 BCE. Our sun is an average sized star about half way down its life cycle. In about five billion years from now, the fuel in the sun will burn out, leaving a cold, dark mass the size of a few miles across, smaller than the size of earth. A star, which is ten times the size of our sun, will have burnt up its fuel in time and collapse on itself into a neutrino star. A neutrino star has massive gravitational pull. If you drop a marshmallow on such a neutrino star, it will produce a force equivalent to a nuclear bomb. However, a star, which is twenty times the size of our sun, will collapse into a black hole with unimaginable gravitational pull. Almost every galaxy in our universe has a black hole in its centre. They are voracious eaters and swallow anything that comes close. Some of them are vast, measuring thousands of light years across with a mass equivalent to millions of suns and some of them are miniscule rogue Black Holes wandering the interstellar space. Despite their reputation of swallowing everything in their path, they do not really go chasing after objects. Ancient Hindu astronomy speaks of stars, other heavenly bodies disappearing, and a star devouring another star. At a crude level, one could think of Rahu swallowing the sun causing the solar eclipse. Ancient scriptures tell us about stars swallowing other stars. It has been described as a bottomless pit into which everything disappears. However, they do have a bottom where the star has condensed into a tiniest mass. Even though the size is tiny, the mass remains the same. For example, when our sun collapses into a dark mass the size of a few miles across, our earth will stay in the same place with the same gravitational pull of the sun. If we set off from the earth in a spacecraft and travel about 26000 light years towards the centre of our Milky Way galaxy we will reach the constellation of Sagittarius. There is an area within the constellation where nothing can be seen. This has been termed Sag A*. As we reach the edge of this area, the time slows down enormously. Every minute spent in this zone called the ‘event horizon’ is equal to about a thousand years on earth. If you manage to cross the ‘Event horizon’ the time stops for you. In Hindu mythology, Brahma, the creator of the universe said to have a life span of billions of years and his one day is equal to thousands of earth years. Is it possible that the author of this hymn was indicating the event horizon and issues with the time space continuum? Mandokya Upanishad describes the day of creator as 4.5 billion years of human time as day the same as night. If we remember the big bang occurred around 13.8 billion years ago and the stars were formed around 9 million years ago, it seems a bit more than coincidence that these numbers match. Black holes do not just exist in the centre of galaxies, but there are rogue ones wandering around the galaxies devouring anything that came in their path. Our own galaxy has at least half a dozen such rogue black holes. What do these black holes have? In a word, a lot of nothing. That is not entirely true. Anything that gets into the clutches of its gravitational pull gets compacted into small objects. A regular sized black hole can compact a mountain the size of Mount Everest to the size of a grain of sand or less. Our own home planet can be compacted to the size of an eyeball. Supermassive black holes are another matter altogether. They would reduce our home planet to atomic size or less. They have masses equivalent to millions or even billions of suns. Once anything reaches the centre of the Black Hole it will come to the region of ‘Singularity’ and all objects merge into this ‘Singularity’. We know that the big bang started with the ultimate example of Singularity – a tiny speck 13.8 billion years ago and it is still expanding. Coming to the region of ‘Event horizon’ or the point of no return. When and if you manage to reach the area just before ‘Event horizon’ area, every minute spent there is equal to thousand years at home on earth. If you manage to cross the event horizon, someone looking from earth will see you frozen in time. However, nothing is infinite. Stephen Hawking theorises that there is a “leak” from the black holes at an infinitesimal slow rate. You will have to wait a trillion or two earth years before you can escape. As you fall through the black hole, you are stretched and shred to pieces and as you reach the centre, you become one with the black hole. You have reached “Singularity”. This begs the question or several questions. Did the ancient Indians know about the black holes and the Event horizon five thousand years ago? Did they know that the time moves slower nearer the centre of gravity than, say a global positioning satellite (GPS)? Did they know that a minute near the event horizon is equal to thousands of earth years? When they quoted the creator’s time as millions or billions of years, were they being metaphorical? When one becomes one with the Black Hole in ‘Singularity’, is one merging with the Creator, as Hindu’s believe? So far, no black hole has been imaged. That is until now. The black Hole in Sag A* in the centre of our own Milky Way galaxy, is due to have its dinner within next twelve months or do. A gas cloud is nearing the event horizon and every capable telescope is being pointed at this spot to catch a once in a millennium occurrence. The entire globe is being converted into a massive telescope to watch this feeding frenzy. We will not be able to see the black hole, but we can see what happens to the Gas cloud G. We will be able to see left overs at the table.